<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id='test'></div>
    <script src="./js/react.development.js"></script>
     <script src="./js/react-dom.development.js"></script>
     <script src="./js/babel.min.js"></script>
     <script type="text/babel">

         class Wantter extends React.Component{
            state = {
                hot:true
            }

            setHot = ()=>{
                // setHot(){} 在Weatter 的原型对象上
                // setHot = function(){} 在Watter 的实例对象上 
                this.setState({
                    hot:!this.state.hot
                })
            }

             render(h) {
                 console.log(this);
                return <h2 onClick={this.setHot}>今天天气很{this.state.hot?'炎热':'凉爽'}</h2>   
             }
         }
         ReactDOM.render(<Wantter/>, document.querySelector('#test'))
     </script>
</body>
</html>